Every workout should start with a warm up, even strength training. So before you pick up those dumbbells, take some time to warm up. Five minutes of cardio is enough to get your blood flowing and increased blood flow increases muscles contraction by 55 percent. So warming up helps your muscles work more.
Not only that, but even a five minute warm up decreases your body's perceived exertion of how hard you are working. Yep, a little warm up can make things feel easier. If that doesn't convince you to spend five minutes on the elliptical before pumping iron, let me just remind you warming up is one of the best ways to prevent injuries. Since even a minor injury can hinder a workout, you really want to avoid getting hurt.